tomwhitwell/chord-organ

chord-organ's Issues

Sound cuts out

Hope this is OK to post here. I've just built a chord organ from a PCB set from thonk as I had most of the parts. Its working when I first turn it on but after a varying amount of time the sound fades out and leaves some quiet noise.

If I tap the joints around the op-amp it comes back for a while but fades out again. It can work for anywhere between around a minute and a few seconds.

I've changed the TL074 and reflowed the points of the op-amp and most things in that area, continuity tested the dac to output path and can't see anything wrong.

I've used 1n4148 in place of the BAT42 and 10r resistors in place of ferrites but don't think that would cause it. Any ideas?

Top led's and trigger led makes a gate voltage sound whenever they blink

So I´ve had the Chord organ module for about one month now. It was working fine but sometimes it would suddenly go quiet and then after 1-10 minutes it would go back to full volume. But today once I got another module (2hp vca) the volume went down, and wouldn´t go back up. And then every time any of the leds would blink a sorta blip noise would be made and when i had the extra wave forms on the firmware, when ever i was one the second or third page of wave forms the leds would blink and make sound similar to the trigger out sound. It would also make an obnoxious hum too I tried re-looking at solder joints, redoing the firmware, and adjusting the volume on the blue box but nothing works. Please help.

Can't get full output range with ROOT CV input

I have a Chord Organ that I built a couple of years ago from a Thonk kit, just noticed an issue today. If I use the ROOT control knob I get a full 4 octave range from the output - 65 to 1040 Hz. If I instead use a 0-5 volt signal at the ROOT input, I only get a little over 3 octaves out - 65 to about 622 Hz; the output stops responding with anything over about 3.28 volt CV in. I also have a Radio Music built a few years ago so I loaded the Chord Organ firmware onto that, I get the same results, can't get the full 4 octaves with CV in. I'm running what appears to be the most recent firmware, Chor_Organ_0.6.hex, on both units.

Is this considered "normal" behavior? If not, where should I look?

TIA,
Dennis Kulpa

How to convert Chord Organ into a Radio Music?

I have no idea about programming or "Teensy"(?) How would I go about converting the Chord Organ into a Radio Music? Thank you

Root note is sometimes unsteady with cv modulation

Comment on muff's :

https://www.muffwiggler.com/forum/viewtopic.php?p=2643653#2643653

My chord organ changes its root note from time to time. This happens either when I have lfo patched into root note or cv sequence. Usually, the root note holds for some time than it changes returns back etc... It doesn't happen when I don't have anything plugged into root note. On the other hand, the root note doesn't changes when I'm modulating chord.

I've uploaded audio from it for better understanding:
Chord organ issue

https://hearthis.at/tasun/chord-organ-issue/

In this case I'm modulating root note with voltage block, you can hear it in 5th second.

Chord organ no longer outputting chord just glitch + error that Chord Organ_0.6 is too large 4 Teensy

I bought a used chord organ from Control in Brooklyn (so I didn't solder it) about 11 months ago. It was working fine but overtime has become unstable in its sound outputs. Root seems to function/track properly but the module is no longer outputting chords just what I'd describe as dirty oscillator forms (e.g. sine wave sounds more like a saw with rich harmonics but not a chord). I tried to reinstall the firmware but am getting an error message that 0.6 hex is too large a file so currently operating on 0.5 beta hex 86%. Any suggestions appreciated!

my changes to CHORDORG.TXT are ignored, why?

I have the following problem with my new Chord-Organ, which I bought second hand a couple of days ago: No matter what I change in the CHORDORG.TXT file, the module will still play what it has played since I have it. I made a test and made all 16 chords equal, it will still play the default 16 different chords. What am i doing wrong? Thank you in anticipation.

Chord organ stops working after some time

Hello @TomWhitwell,
i am experiencing weird problems with my chord organ. When i power it on the module works perfect for some time (1-2 minutes) and then stops outputting audio. It seems like the controls still work because the leds still light accordingly to button presses and knob turns. I attached a video of the behavior of the module.

IMG_0467480.mp4

Question about regulating output gain

Hi. Thanks for this great project.

In general use I find the audio output to be too high, and can easily cause clipping. How could I lower output gain in the code?

low volume...

I built the CO today. It seems to work, but has very low volume even with the trimmer turned fully CW.

Assuming that this is not normal, I looked at the schematic and it appears that there might be an issue with the IC4D/IC4A op amp stages. Can you give me an idea of what approximate voltages I should be seeing at the input of IC4D and the outputs of IC4D and IC4A?

One other thing I noticed -- there is a constant background tone of almost exactly 350Hz that doesn't change when I move the knobs. That doesn't seem to divide into the 72?mHz Teensy clock speed well (i.e. with an integer result) so.... ????

I am pretty sure I got the capacitors in their correct locations, but below is a photo of the back board.

i touched up all of the connections involved with the DAC > audio amplifier circuit, with no change.

Oh -- one other thing: I tried both the 0.5 and 0.6 firmwares, and noted that with 0.6, the trigger LED does not come on when a trigger is sent to the TRIGGER input. With 0.5, it does flash with each trigger. Is this intentional?

And finally, both the .hex file and the .zip file at https://github.com/TomWhitwell/Chord-Organ/tree/master/Collateral/Hex%20File are corrupt.

SCALA tuning files issue?

I just finished building the Chord Organ, loaded Ver. 0.6 of the firmware and everything appears to work properly. I then downloaded the SCALA scales.zip file, and followed the instructions to copy a new scale file onto the SD card. I don't hear any dramatic improvements/changes to the chords played. I've tried several different files but regardless which SCALA file I put onto the card, I can't perceive any difference. What am I missing here??

How to put custom wavetables in waves.h?

Is there a software or script to convert custom wavetables to arrays like the ones in waves.h?

Trigger Led is always lit and the tune knob does nothing

Hey Tom, so I built a chord organ awhile back and I haven't been able to resolve my issue. I can go through the wave shapes but the root is very distorted and doesn't work at all. Also the trigger led is always on. When I put cv into the root jack I can here it go through all the notes though. I thought it might be the root pot so I changed it but I am still having the same problem. also when I plugged the teensy in originally, my teensy loaded already had another firmware for a different module on it and im not sure if it loaded that and the Chord Organ firmware. Any help would be greatly appreciated.

Thanks,
Alex

Module LEDs not lighting up anymore

After trying to reinstalling the firmware, no LEDs are lighting up anymore at all. Neither there is any response when pressing the button on the Teensy.
I cannot find anything on this problem on the troubleshooting site.
Also testing via moduletest.cpp.hex (https://github.com/TomWhitwell/RadioMusic/blob/master/Collateral/ModuleTest/README.md)
cannot work, because the button doesn't create any response.
Please help.

Certain wave forms produce a lot of noise

Hey there,

I love my chord organ but the waveform that I'd most like to use, the basic sine wave, has a whole bunch of noise along for the ride. This is true of several of the other waveforms as well. I'm up to date on the latest firmware and I'm presently running the user submitted one with the CV fix, but has been a problem on every firmware.

Any thoughts?

Can't seem to access the additional waveforms

Hi there! I just installed the new firmware (I think), but I can't seem to access the two additional pages of waveforms. I checked that I wanted the waveforms on the firmware page, downloaded the firmware, loaded it onto the module with the teensy-program (it says that it's got 0.5beta installed when I click the teensy button on the module). Pressed the program and reboot, everything went OK, it seemed. I did not upload the config file on the sd-card though, but it appears that's not necessary unless I want to change the chords. Right? I should be able to access the additional waveforms just by pressing the button on the module, right?

Any idea what might be wrong here?

Extra root note sounding on all chords

Hi Tom!
Just installed the new firmware and I love the new waves and the better 1v/oct response. A couple of things though.

The cv response is not quite perfect. Using my Keystep's pitch CV out, some notes are off by a half step, some don't get recognized. Only the next to highest octave tracks correctly. I left the custom option off in the ini file. Should I set that to something? Is there a digical procedure I don't know about?

The other thing is that I actually programmed a whole chord progression, including root movements, but now there's a constant low "root" note, which in my case isn't the real root. I think it's important to be able to program chords that don't have the root at all, or have a transposed root relative to the "0" note.

Anyways, great module, thanks :)

best
Q

Module seems to always be triggering, chord selection seems to add weird harmonics and random reboots.

Hey there,

Yesterday I finished building my Chord Organ, and I've had mixed results using it so far. On initial startup, the four leds blinked in slow sequence since no SD card was in the slot. After the led sequence, the first led lit up flickery and it rebooted itself. After two reboots, it suddenly worked quite ok, the waveforms sounded clean and the chord selection sounded as it should. Now after a few more reboots, the module seems to have a problem again.

The trigger led is always on, when I connect a new cable to one of the ins/outs, the waveform sometimes switches and the module sometimes even reboots! The waveforms sometimes sound distorted and the chord selection seems to be functioning a bit weird. Also when I tap the module, sometimes the waveforms change up a bit or the trigger led skips a few beats... When I check the output of the module on my headphones directly, I only hear garbled audio..

I already checked for shorts but cant find anything obvious.. Let me know how I might be able to troubleshoot, since it's an amazing module when it works:)

possibility of reloading settings at SD card insert

Hi there,

I noticed that my Chord Organ suffers from the same issue as my Radio Music, in that it fails to boot up properly when I apply power to the case (a Doepfer LC6, with a PSU3) with an SD card installed.

That would not be so bad, except that the Chord Organ starts up without an SD card in its default mode, then ignores card inserts, meaning I don't get my custom settings from the card (like extra wavetables).

Radio Music does reset correctly when I insert an SD card - maybe this could be put in the Chord Organ code as well?

Kind regards, erik.